JPS64797B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for manufacturing a rubber airtight terminal used in a compressor for a cold machine such as an electric refrigerator or a room cooler.

Background technology Refrigerators such as electric refrigerators and room coolers use a refrigerant such as Freon gas, which is compressed and liquefied → endothermic vaporization → heat radiation →
It is designed to be cooled by a compression liquefaction refrigeration cycle. A compressor is used in the compression liquefaction process. This compressor has a compression motor housed in a sealed case, and in order to lead out the power supply line of the compression motor from the sealed case in an airtight and insulated manner, as shown in Figures 1 and 2. Rubber airtight terminals are used.

In the figure, reference numeral 1 denotes a metal outer ring made of iron or low carbon steel, which has a cap-like shape as a whole, and has a welding flange 2 facing diagonally downward on the outer periphery of the lower end. In the illustrated example, it has three inwardly facing cylindrical portions 4. A lead wire 6 made of iron/chromium alloy or copper core iron/chromium alloy is hermetically insulated and sealed in each cylindrical part 4 via soda glass 5 such as soda barium glass or soda lime glass. has been done. Reference numeral 7 denotes a silicone rubber formed on the upper surface of the metal outer ring 1 and the glass 5, and has a truncated conical portion 8 rising along the lead wire 6.

The reason why silicone rubber 7 is deposited on the upper surfaces of metal outer ring 1 and glass 5 is as follows. That is, the airtight terminal is fitted into a through hole formed in the airtight case of the compressor from the inside with the silicone rubber 7 facing outward, and the flange 2 is fitted onto the edge of the through hole. It is used by bringing the two into line contact and fixing them together by projection welding. However, since the refrigerant passes through the sealed case, the airtight terminal is also cooled, and moisture in the air is likely to condense on its surface. If the silicone rubber 7 is not applied, the surface of the glass 5 will become wet due to dew condensation, and the withstand voltage or insulation resistance characteristics between the metal outer ring 1 and the lead wire 6 will deteriorate. For this reason, it has been considered to form a water-repellent coating such as silicone resin on the surface of the glass 5, but it is difficult to form a water-repellent coating only on the surface of the glass 5, and if the surface of the lead wire 6 is If it adheres, it will no longer be possible to weld the terminal plate.
Therefore, if water-repellent silicone rubber 7 is formed on the upper surfaces of the metal outer ring 1 and the glass 5, the creepage distance between the metal outer ring 1 and the lead wire 6 will increase, and the silicone rubber 7 will Water repellency can prevent deterioration of withstand voltage and insulation resistance characteristics between the metal outer ring 1 and the lead wire 6.

Now, such a rubberized airtight terminal has conventionally been manufactured by a process as shown in FIG. That is, a metal outer ring 1, a glass tablet 5' in which fine glass powder is kneaded with an organic binder, press-molded and then calcined to burn out the organic binder, and a lead wire 6 are prepared, and these are made of graphite. Assemble it in the predetermined position using the sealing jig and approximately
The glass tablet 5' is melted by heating to about 1000° C., and the lead wire 6 is hermetically and insulated sealed to the metal outer ring 1 via the glass 5. Next, finish plating such as electroless nickel plating is applied to the exposed parts of the metal outer ring 1 and the lead wires 6, and then a primer treatment is applied to the upper surfaces of the metal outer ring 1 and the glass 5, followed by room-temperature vulcanization. The silicone rubber 7 is formed by casting.

However, in the above-described conventional manufacturing method, the silicone rubber 7 tends to have poor adhesion, and may peel off during transportation or attachment to a sealed case.

DISCLOSURE OF THE INVENTION Therefore, it is an object of the present invention to provide a method for manufacturing a rubber hermetic terminal with high rubber adhesion strength.

To summarize, this invention is characterized by forming rubber on the upper surface of the metal outer ring and glass in a state where oxide exists on the exposed surfaces of the metal outer ring and the lead wire, and then forming a rubber layer on the metal outer ring and the upper surface of the glass as necessary. Remove oxide from exposed surfaces of outer ring and leads.

In other words, forming rubber on the finish plating surface has a low adhesion strength because the finish plating surface is smooth and chemically stable, but it is difficult to form rubber on the metal outer ring and the finish plating surface. When rubber is deposited on the surface of the lead wire in the presence of oxide, the surface becomes minutely uneven and the oxide blends with the primer, resulting in a significant increase in adhesive strength.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows a manufacturing process diagram of this invention. first,
As before, prepare the metal outer ring 1, the glass tablet 5', and the lead wire 6, assemble them in predetermined positions using a graphite sealing jig, and place them in a neutral or weakly reducing atmosphere. Inside, the whole is heated to about 950 to 1050°C to melt the glass tablet 5', and the lead wire 6 is hermetically and insulated inside each cylindrical part 4 of the metal outer ring 1 through the glass 5. and seal. Thereafter, the exposed surfaces of the metal outer ring 1 and the lead wires 6 are finished plated to a thickness of 3 μm by electroless nickel plating. Next, this airtight terminal is heated in an oxidizing atmosphere at 250° C. for 1 hour to oxidize the finished plating surface to the extent that the finish is slightly discolored. Subsequently, silicone rubber 7 is deposited on the upper surfaces of the metal outer ring 1 and the glass 5 by casting. Since the oxide film produced here is very thin, it will not cause any problem in subsequent welding or cluster connections.

When a peel test was conducted on the silicone rubber 7 for the rubberized airtight terminal manufactured as described above, it was found that the metal outer ring 1 and the lead wire 6 were separated from the silicone rubber 7.
Adhesion failure caused by peeling at the interface was 0%. On the other hand, in a peel test of a rubber airtight terminal manufactured by a conventional method, adhesion failure occurred by 3 to 5%.

In addition, although the method of the above embodiment corresponds to the conventional method and has been described using electroless nickel plating as the final plating, electric nickel plating may also be used.

Furthermore, if necessary, silicone rubber 7 may be deposited and formed before the final plating, and then the final plating may be performed.

Furthermore, the oxidation treatment of the exposed surfaces of the metal outer ring 1 and the lead wires 6 may be performed not only by thermal oxidation in an oxidizing atmosphere as shown in the above embodiments, but also by chemical oxidation.

[Brief explanation of drawings]

FIG. 1 is a plan view of an example of a rubber airtight terminal. FIG. 2 is a cross-sectional view of the airtight terminal shown in FIG. 1 taken along the - line. FIG. 3 is a process diagram for explaining a conventional method of manufacturing a rubber hermetic terminal. FIG. 4 is a process diagram for explaining a manufacturing method of an embodiment of a rubber airtight terminal according to an embodiment of the present invention. 1...Metal outer ring, 5...Glass, 6...Lead wire, 7...Silicone rubber.

Claims (1)

[Scope of Claims] 1. The method includes the steps of: hermetically and insulatingly sealing the lead wire into the through hole of the metal outer ring through the glass; and forming a rubber coating on the surface of the metal outer ring and the glass. A method for manufacturing an airtight terminal with rubber, the method comprising the step of depositing rubber on the metal outer ring and the upper surface of the glass in a state where an oxide is present on the surface of the metal outer ring and the lead wire. A method for manufacturing airtight terminals.